Amino acid sidechains adopt different conformational states, or rotamers. Rotamers from the Dunbrack backbone-dependent library or the Richardson "penultimate" library can be viewed, evaluated, and incorporated into structures with the Rotamers tool. A residue can be changed into a different conformation of the same type of amino acid or mutated into a different type. Rotamer torsion angles and library probability values are listed in a dialog, along with (optionally) hydrogen bonds, clashes, and agreement with electron density data. Only rotamers chosen in the list are displayed. When a single rotamer is chosen, it can be incorporated into the structure. The image includes 2D labels.

Mutations that inactivate the tumor suppressor p53 are found in over 50% of human cancers, and most of the cancer-associated mutations are within its DNA-binding domain. The image shows a tetramer of the p53 DNA-binding domain complexed with DNA (Protein Data Bank entry 2ac0). The tetramer subunits are shown as light blue, green, orange, and yellow ribbons, with red spheres marking several major "hot spots" of mutation. The DNA is shown in purple and blue. (More samples...)